https://github.com/LostCityRS/Engine/blob/e90b2f48d92394253e9e35d886ec2e419b5b3770/src/network/os1/server/codec/game/MessageGameEncoder.ts#L12 Packets with a -1 or -2 size need their sizes calculated at runtime by overriding the `test` function. See 2004scape...
https://github.com/LostCityRS/Engine/blob/e90b2f48d92394253e9e35d886ec2e419b5b3770/src/network/os1/server/codec/game/MessageGameEncoder.ts#L12
Packets with a -1 or -2 size need their sizes calculated at runtime by overriding the
testfunction. See 2004scape...